Method of controlling the growth of plants

ABSTRACT

A novel salt of p-nitrobenzenesulfonylurea having the formula   WHICH IS FORMED BY THE REACTION OF P-NITROBENZENESULFONYLUREA WITH ETHANOLAMINE AND ACETONE. This compound has herbicidal activity.

United States Patent 634,963 11/1963 Belgium Primary ExaminerJames 0.Thomas, Jr. AnorneysPaul C. Krizov, David D. Centola and Robert C.

Griesbauer ABSTRACT: A novel salt of p-nitrobenzenesulfonylurea havingthe formula which is formed by the reaction ofp-nitrobenzenesulfonylurea with ethanolamine and acetone.

This compound has herbicidal activity.

METHOD OF CONTROLLING THE GROWTH OF PLANTS This invention relates to anovel salt of p-nitrobenzenesulfonylurea, its preparation and herbicidaluse.

in the study of herbicidal activity of substituted benzenesultonylureasa multitude of the derivatives and their amine slats were prepared. Oneof the procedures utilized in the preparation of the amine salts of thesubstituted benzenesulfonylurea was to react the appropriate urea withthe amine in a solvent such as acetone, benzene, ether and the like.

When p-nitrobenzenesulfonylurea was reacted with ethanolamine in etheror benzene the normal ethanolamine slat was obtained. However when thereaction was carried out in acetone the isopropylidineaminoethanol saltwas obtained instead of the ethanolamine salt.

The anionic portion of the salts of substituted benzenesult'onylurea isa resonance hybrid masbsmsemss which has the terminology of isourea" orurea" depending upon the charge location. For convenience theterminology isourea" and the h y brid formula v [W SOPNJLWT O CH CH I e33 WANNA. mnomcmon ADP- 0 ll HzNCHzCHaOH 01130011;

HOGHQCHZNHI (CHQ CO CHs The reaction can be carried out at temperaturesin the approximate range of room temperature to refluxing temperature ofthe mixture. Temperatures below room temperature can be used, howeverthere should be sufficient reaction time for completeness of reaction.

As is seen from the above reaction scheme the three components arepresent in an equimolar ratio. For convenience the ethanolamine ispresent in a slight excess and a larger excess of acetone is used sothat it may act as a solvent.

Preparation of p-nitrobenzeneurea is well known in the art and one ofthe methods is illustrated in the examples. In the examples all weightsare expressed as parts by weight unless otherwise designated.

EXAMPLE 1 Preparation of p-nitrobenzenesult'onylurea is according to thefollowing procedure:

To a suitable vessel, equipped with stirring means and reflux apparatus,was charged l2l parts p-nitrobenzenesulfonamide, 49 parts potassiumcyanate, 744 pans ethanol and 240 parts water. The mixture was refluxedfor IS hours and then cooled slowly to roomtemperature. The resultantsolid was filtered off, washed with acetone and dried. An percent yieldwas obtained melting at 225-226 C.

Forty parts of potassium p-nitrobenzenesult'onylisourea was dissolved in650 parts warm water and acidified with hydrochloric acid. The solidp-nitrobenunesulfonylurea was filtered off, washed with water and dried.An 82 percent yield was obtained melting at l-l 97 C.

EXAMPLE 2 Preparation of isopropylidineaminoethanol salt ofpnitrobenzenesulfonylisourea from urea, ethanol and acetone is accordingto the following procedure:

To a suitable vessel equipped with a stirring means, was charged 36parts acetone and 4.5 parts p-nitrobenzenesulfonylurea. To the resultantmixture was added 1.2 pans ethanolamine and the mixture stirred at about25 C. for 4 hours. The solid was filtered off and dried. An 89 percentyield of the desired product was obtained melting at l30l 3 1 C.

EXAMPLE 3 Preparation of isopropylidineaminoethanol salt ofpnitrobenzenesulfonylisourea from ethanolamine" salt ofpnitrobenzenesulfonylisourea and acetone is according to the followingprocedure:

To a suitable vessel equipped with a stirring means and a refluxapparatus was charged with 2.6 parts ethanolamine salt ofp-nitrobenzenesulfonylisourea and l20 parts acetone. The resultantmixture was refluxed for about 2 to 3 hours and allowed to standovernight at room temperature. The solid was removed by filtration anddried yielding the desired compound, melting at 13 ll33 C., in a 100percent yield.

The term "plant system as used herein and in the appended claims meansgerminant seeds, emerging seedlings and established vegetation includingthe roots and above-ground portions.

This compound has been found to exhibit both preemergent andpostcinergent herbicidal activity as illustrated by the followingexamples:

EXAMPLE 4 PREEMERGIENT ACTIVITY A good grade of top soil is placed inaluminum pans and compacted to a depth of three-eighths inch to one-halfinch from the top of each pan. A predetermined number of seeds of eachof several plant species are placed on the top of the soil in the pans.

The seeds are covered with a three-eighths inch layer of prepared soiland the pans leveled. The herbicidal composition is then applied byspraying the surface of the top layer of soil, prior to watering theseeds, with a solution containing a sufficient amount of activeingredient to obtain the desired rate per acre on the soil surface.Initial watering is carried out by permitting the soil to absorbmoisture through the apertured bottom of the pans.

The seed containing pans are placed on a wet sand bench and maintainedfor approximately 14 days under ordinary conditions of sunlight andwatering. The plants are observed at the end of approximately 14 daysand the results recorded The herbicidal activity index is based on theaverage percent germination of each seed lot. The activity index isconverted to a relative numerical scale for the sake of brevity andsimplicity in the examples.

The preemergent herbicidal activity index used in the following exampleis defined as follows:

Numerical Herbtcidal Scale Activity None I Slight 2 Moderate 3 SevereThe compound was applied at the indicated rates. The results are shownin table I.

EXA M PLE POSTEM ERGE NT ACTIVITY Numerical Homicidal Scale Activity 0None 1 Slight 2 Moderate 3 Severe 4 Plants dead The results are listedin table I.

HERBICIDAL ACTIVITY Preemergent Poutemergent Morning Glory l 0 Wild OatBnorne Rye Grass Radish Sugnr Beet Cotton Corn Fonnil Barnyard (FirmsCrab Gram Pigweed Soybean Wild Buckwheat Tomnto Sorghum 2 Rice Inaddition to having general herbicidal activity this compound iseffective against the perennial grasses, Johnson Grass, Bermuda Grassand Quack Grass.

EXAMPLE 6 HERlBIClDAL ACTIVITY ON PERENNIAL GRASSES The chemical wasapplied to established plants, growing in 3 inch pots, at a rateequivalent to 20 gallons per acre of in solution containing 1 percentaerosol MA- (sodium dihexylsulfosuccinate) and an amount of the activecomponent to be equivalent to 20 pounds per acre or 10 pounds per acre.The sprayed plants were placed in a greenhouse and the effects wereobserved after 4 and 15 weeks. Established plants are 6 to 8 inch tall,Quack Grass and Bermuda Grass and l2 and 15 inch tail Johnson Grass.

The herbicidal activity index. used in this example is based as follows:

The herbicidal compositions of this invention comprise the activeingredient and one or more herbicidal adjuvants which can be solid orliquid extenders, carriers, diluents, conditioning agents and the like.Preferred herbicidal compositions containing the active ingredient ofthis invention have been developed so that the active ingredient can beused to the greatest advantage to modify the growth of plant systems insoil. The: preferred compositions comprise certain wettable powders,aqueous suspensions, dust formulations, granules emulsitiable oils andsolutions in solvents. In general these preferred compositions can allcontain one or more surfaceactive agents.

Surface-active agents which can be used in the herbicidal compositionsof this invention are set out, for example in Searle U.S. Pat. No.2,426,4l7, Todd U.S. Pat. No. 2,655,447, Jones U.S. Pat. No. 2,4l2,5l0and lLenher U.S. Pat. No. 2,l 39,276. A detailed list of such agents isalso set forth by .I. W. Mc'Cutcheon in Soap and Chemical Specialties,"Nov. 1947, page 801i et seq, entitled Synthetic Detergents"; Detergentsand Emulsifiers--Up to Date" (1960), by J. W. McCutcheon. Inc., andBulletin E--607 of the Bureau of Entomology and Plant Quarantine of theU.S.D.A. In general less than 15 parts by weight of the herbicidalcomposition.

lOlOl S 0383 Wettable powders are water-dispersible compositionscontaining the active ingredient, an inert solid extender and one ormore wetting and dispersing agents. The inert solid extenders areusually of mineral origin such as the natural clays, diatomaceous earthand synthetic minerals derived from silica and silicate. Examples ofsuch extenders include kaolinites, attapulgite clay and syntheticmagnesium silicate.

Preferred wetting agents are alkyl benzene and alkyl naphthalenesulfonates, sulfated fatty alcohols, amines or acid amides, long chainacid esters of sodium isothionate, esters of sodium sulfosuccinate,sulfated or sulfonated fatty acid esters, petroleum sulfonates,sulfonated vegetable oils and ditertiary acetylinic glycols. Preferreddispersants are methyl cellulose, polyvinyl alcohol, sodium 'ligninsulfonates, polymeric alkyl naphthalene sulfonates, sodium naphthalenesulfonate, polymethylene bisnaphthalenesulfonate and sodium N-methyl-N-(long chain acid) taurates.

The wettable powders compositions of this invention usually contain fromabout 5 to about 95 parts of active ingradient, from about 0.25 to about3.0 parts of wetting agent, from about 0.25 to about 7 parts ofdispersant and from about 4.5 to about 94.5 parts of inert solidextender, all parts being by weight of the total composition. Whererequired from about 0.1 to 2.0 parts by weight of the solid inertextender can be replaced by a corrosion inhibitor or antifoaming agentor both.

Dusts are dense finely divided particulate compositions which areintended for application to the soil in dry form. Dusts arecharacterized by their free-flowing and rapid settling properties sothat they are not readily windborne to areas where they are of no value.Dusts contain primarily the active ingredient and a dense, free-flowing,finely divided particulate extender. However, their performance issometimes aided by the inclusion of a wetting agent such as those listedhereinbefore under wettable powder compositions and convenience inmanufacture frequently demands the inclusion of an inert, absorptivegrinding aid. Suitable classes of grinding aids are natural clays,diatomaceous earth and synthetic minerals derived from silica orsilicate. Preferred grinding aids include attapulgite clay, diatomaceoussilica, synthetic fine silica and synthetic calcium and magnesiumsilicates.

Granules are physically stable particulate compositions comprising theactive ingredient adhering to or distributed through a basic matrix ofan inert, finely divided particulate extender. In order to aid leachingof the active ingredient from the particulate, a surfactant such asthose listed hereinbefore under wettable powders can be present in thecomposition. Natural clays, pyrophyllites and vermiculite are examplesof operable classes of particulate mineral extenders. The preferredextenders are the porous, absorptive, preformed particles such aspreformed and screened particulate attapulgite or heat expended,particulate vermiculite, and the finely divided clays such as kaolinclays, hydrated attapulgite or bentonitic clays. These extenders aresprayed or blended with the active ingredient to form the herbicidalgranules.

The mineral particles which are used in the granular herbicidalcompositions of this invention usually have a size range of 10 to l00mesh, but preferably such that a large majority of the particles havefrom 14 to 60 mesh with the optimum size being from to 40 mesh. Clayhaving substantially all particles between l4 and 80 mesh and at leastabout 80 percent between 20 and 40 mesh is particularly preferred foruse in the present granular compositions. The term mesh" as used hereinmeans U.S. Sieve Series.

The granular herbicidal compositions of this invention generally containfrom about l part to about 30 parts by weight of the active ingredientper 100 parts by weight of clay and 0 to about 5 parts by weight ofwetting agent per 100 parts by weight of clay. The preferred herbicidalgranular compositions contain from about 5 parts to about parts byweight of the active ingredient per 100 parts by weight of clay.

The herbicidal compositions of this invention can also contain otheradditaments, for example, fertilizers, other herbicides, pesticides andthe like, used as adjuvant or in combination with any of theabove-described adjuvants.

The compound of this invention may be used in combination with knownherbicides in order to provide enhanced biological effectiveness. Theuse of various herbicides in combination at the time of a singleapplication or sequentially is common in practice. Herbicides which maybe used in combination with the compound of this invention include butare not limited to: substituted phenoxyaliphatic acids such as 2,4-dichlorophenoxyacetic acid; 2,4,5-trichlorophenoxyacetic acid,2-methyl-4-chlorophenoxyacetic acid and the salts, esters and amidesthereof; triazine derivatives, such as 2-chloro-4-ethylamino-6-isopropylamino-s-triazine; 2,4-bis(isopropylamino)-6-methoxy-s-triazine and2-methylmercapto-4,6-bis(isopropylamino)-s-triazine; urea derivativessuch as 3-(3,4-dichlorophenyl)-l ,l-dimethylurea and3-(mtrifluoromethylphenyl)-l,l-dimethylurea I and 3-(3,4-dichlorophenyl)- l -methoxy-l -methylurea; pyridylium derivatives suchas l:l'-ethylene-2,Z-dipyridyliurn dihalide; acetanilides such asN-isopropyl-alpha-chloroacetanilide, and 2-chloro-2"-diethyl-N-methoxymethyl acetanilide; acetamides such asN,N-diallyl-alphachloroacetamide, carbamates such asethyl-N,N-di-n-propylthiol-carbamate, and 2,3dichloroallyldiisopropylthiolcarbamate; substituted uracils such as 5-bromo-3-sec-butyl-6-methyluracil, substituted anilines such asN,N-dipropyl-alpha,alpha,alpha,-trifluoro-2,6-dinitro-ptoluidine;pyridazone derivatives such as 5-amino-4-chloro-2-phenyl-3-(2H)-pyridazinone, and the like.

Fertilizers useful in combination with the active ingredients include,for example ammonium nitrate, urea and superphosphate. Other usefuladditaments include materials in which plant organisms take root andgrow such as compost, manure, humus, sand and the like.

When operating in accordance with the present invention, effectiveamounts of the compound of this invention is dispersed on or in the soilor plant growth media and applied to plant systems in any convenientfashion. Application to the soil or growth media can be carried out bysimply mixing with the media, by applying to the surface of the soilandthereafter dragging or discing into the soil to the desired depth, orby employing a liquid carrier to accomplish the penetration andimpregnation. The application of liquid and particulate solid herbicidalcompositions to the surface of soil or to plant systems can be carriedout by conventional methods, e.g., power dusters, boom and hand sprayersand spray dusters. The compositions can also be applied from airplanesas a dust or a spray because of their effectiveness at low dosages. In afurther method, the distribution of the active ingredient in soil can becarried out by admixture with the water employed to irrigate the soil.In such procedures, the amount of water can be varied with the porosityand water-holding capacity of the soil to obtain the desired depth ofdistribution of the herbicide.

The application of an effective or herbicidal amount of the compound ofthis invention to the soil or growth media or plant systems is essentialand critical for the practice of one embodiment of the presentinvention. The exact amount of active ingredient to be employed isdependent upon the response desired in the plant as well as such otherfactors as the plant species and stage of development thereof, thespecific soil and depth at which the active ingredients are distributedin the soil and the amount of rainfall.

The inert finely-divided solid extender for the dusts can be ofvegetable or mineral origin. The solid extenders are characterized bypossessing relatively low surface areas and are poor in liquidabsorption. Suitable inert solid extenders for herbicidal dusts includemicaceous talcs, pyrophyllite, dense kaolin clays, ground calciumphosphate rock and tobacco dust. The dusts usually contain from abut 0.5to 99 parts active ingredient, 0 to 500 parts dense solid extender, allparts being by weight based on the total weight of the dust.

The wettable powders described above may also be used in the preparationof dusts. While such wettable powders could be used directly in dustform, it is more advantageous to dilute them by blending with the densedust diluent. In this manner, dispersing agents, corrosion inhibitors,and antifoam agents may also be found as components of a dust.

Einulsifiable oils are usually solutions of the active ingredient inwater-immiscible solvents together with a surfactant. Suitablesurfactants are anionic, cationic and nonionic such as alkyl arylpolyethoxy alcohols, alkyl and alltyl aryl polyether alcohols,polyethylene sorbitol or sorbitan fatty acid esters, polyethylene glycolfatty esters, fatty alkyllol amide condensates, amine salts of fattyalcohol sulfates together with long chain alcohols and oil solublepetroleum sulfonates or mixtures thereof. The emulsifiable oilcompositions generally contain from about to 95 parts active ingredient,about 1 to parts surfactant and about 4 to 94 parts solvent, all partsbeing by weight based on the total weight of emulsifiable oil.

In foliar treatment for the control or modification of vegetativegrowth, the active ingredient is applied in amounts from about 1 toabout 50 or more pounds per acre. In applications to soil for thecontrol or modification of the growth of germinant seeds, emergingseedlings and established vegetation, the active ingredient is appliedin amounts from about 1 to about 50 or more pounds per acre. It isbelieved that one skilled in the art can readily determined from thisspecification, including examples, the application rate for any specificsituation.

The term soil" and growth media" are employed in the presentspecification and claims in their broadest sense to be inclusive of allconventional soils as defined in Websters New international Dictionary,Second Edition, Unabridged (1961). Thus, the terms refer to anysubstance or media in which vegetation may take root and grow, and areintended to include not only earth but compost, manure, muck, humus,sand and the like, adapted to support plant growth.

While the illustrative embodiments of the invention have been describedhereinbefore with particularity, it will be understood that variousother modifications will be apparent to and can readily be made by thoseskilled in the art without departing from the scope and spirit of theinvention, Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and description set forthherein but rather the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present inventionincluding all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains.

What is claimed is:

1. Method of controlling the growth of plants which comprises contactingthe plant system to a herbicidal effective amount ofisopropylidineaminoethanol salt of pnitrobenzenesulfonylisourea.

2. Method of controlling perennial grasses which comprises applying tothe grasses a herbicidal effective amount of isopropylidineaminoethanolsalt of p-nitrobenzenesulfonylisourea.

2. Method of controlling perennial grasses which comprises applying tothe grasses a herbicidal effective amount of isopropylidineaminoethanolsalt of p-nitrobenzenesulfonylisourea.